// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
// Distributed under the MIT License (http://opensource.org/licenses/MIT)

#pragma once

#ifndef SPDLOG_HEADER_ONLY
#include <spdlog/details/file_helper.h>
#endif

#include <spdlog/common.h>
#include <spdlog/details/os.h>

#include <cerrno>
#include <chrono>
#include <cstdio>
#include <string>
#include <thread>
#include <tuple>

namespace spdlog {
namespace details {

    SPDLOG_INLINE file_helper::file_helper(const file_event_handlers& event_handlers) : event_handlers_(event_handlers) {}

    SPDLOG_INLINE file_helper::~file_helper() { close(); }

    SPDLOG_INLINE void file_helper::open(const filename_t& fname, bool truncate)
    {
        close();
        filename_ = fname;

        auto* mode = SPDLOG_FILENAME_T("ab");
        auto* trunc_mode = SPDLOG_FILENAME_T("wb");

        if (event_handlers_.before_open)
        {
            event_handlers_.before_open(filename_);
        }
        for (int tries = 0; tries < open_tries_; ++tries)
        {
            // create containing folder if not exists already.
            os::create_dir(os::dir_name(fname));
            if (truncate)
            {
                // Truncate by opening-and-closing a tmp file in "wb" mode, always
                // opening the actual log-we-write-to in "ab" mode, since that
                // interacts more politely with eternal processes that might
                // rotate/truncate the file underneath us.
                std::FILE* tmp;
                if (os::fopen_s(&tmp, fname, trunc_mode))
                {
                    continue;
                }
                std::fclose(tmp);
            }
            if (!os::fopen_s(&fd_, fname, mode))
            {
                if (event_handlers_.after_open)
                {
                    event_handlers_.after_open(filename_, fd_);
                }
                return;
            }

            details::os::sleep_for_millis(open_interval_);
        }

        throw_spdlog_ex("Failed opening file " + os::filename_to_str(filename_) + " for writing", errno);
    }

    SPDLOG_INLINE void file_helper::reopen(bool truncate)
    {
        if (filename_.empty())
        {
            throw_spdlog_ex("Failed re opening file - was not opened before");
        }
        this->open(filename_, truncate);
    }

    SPDLOG_INLINE void file_helper::flush()
    {
        if (std::fflush(fd_) != 0)
        {
            throw_spdlog_ex("Failed flush to file " + os::filename_to_str(filename_), errno);
        }
    }

    SPDLOG_INLINE void file_helper::sync()
    {
        if (!os::fsync(fd_))
        {
            throw_spdlog_ex("Failed to fsync file " + os::filename_to_str(filename_), errno);
        }
    }

    SPDLOG_INLINE void file_helper::close()
    {
        if (fd_ != nullptr)
        {
            if (event_handlers_.before_close)
            {
                event_handlers_.before_close(filename_, fd_);
            }

            std::fclose(fd_);
            fd_ = nullptr;

            if (event_handlers_.after_close)
            {
                event_handlers_.after_close(filename_);
            }
        }
    }

    SPDLOG_INLINE void file_helper::write(const memory_buf_t& buf)
    {
        size_t msg_size = buf.size();
        auto data = buf.data();
        if (std::fwrite(data, 1, msg_size, fd_) != msg_size)
        {
            throw_spdlog_ex("Failed writing to file " + os::filename_to_str(filename_), errno);
        }
    }

    SPDLOG_INLINE size_t file_helper::size() const
    {
        if (fd_ == nullptr)
        {
            throw_spdlog_ex("Cannot use size() on closed file " + os::filename_to_str(filename_));
        }
        return os::filesize(fd_);
    }

    SPDLOG_INLINE const filename_t& file_helper::filename() const { return filename_; }

    //
    // return file path and its extension:
    //
    // "mylog.txt" => ("mylog", ".txt")
    // "mylog" => ("mylog", "")
    // "mylog." => ("mylog.", "")
    // "/dir1/dir2/mylog.txt" => ("/dir1/dir2/mylog", ".txt")
    //
    // the starting dot in filenames is ignored (hidden files):
    //
    // ".mylog" => (".mylog". "")
    // "my_folder/.mylog" => ("my_folder/.mylog", "")
    // "my_folder/.mylog.txt" => ("my_folder/.mylog", ".txt")
    SPDLOG_INLINE std::tuple<filename_t, filename_t> file_helper::split_by_extension(const filename_t& fname)
    {
        auto ext_index = fname.rfind('.');

        // no valid extension found - return whole path and empty string as
        // extension
        if (ext_index == filename_t::npos || ext_index == 0 || ext_index == fname.size() - 1)
        {
            return std::make_tuple(fname, filename_t());
        }

        // treat cases like "/etc/rc.d/somelogfile or "/abc/.hiddenfile"
        auto folder_index = fname.find_last_of(details::os::folder_seps_filename);
        if (folder_index != filename_t::npos && folder_index >= ext_index - 1)
        {
            return std::make_tuple(fname, filename_t());
        }

        // finally - return a valid base and extension tuple
        return std::make_tuple(fname.substr(0, ext_index), fname.substr(ext_index));
    }

}  // namespace details
}  // namespace spdlog
